The Cuckoo roller or courol (Leptosomus discolor), is the only bird in the family Leptosomidae, which is usually placed in the order Coraciiformes, which also includes the kingfishers, bee-eaters and rollers. However, its position is not very clear. Morphological evidence may suggest a placement in or near to Falconiformes. In the rather comprehensive DNA study by Hackett et al, this and the hoatzin are the only two birds whose position is unclear, although the cuckoo roller seems to be at the root of a group that contains the Trogoniformes, Bucerotiformes, Piciformes, and Coraciiformes.